1. Field of the Invention
The present invention relates generally to an orthopedic surgical procedure, and more particularly to a method and apparatus for external fixation of small bones.
2. Description of the Related Art
In various orthopedic surgical procedures, it is often necessary to secure two or more portions of bone in a relatively fixed relationship to each other. This need is often a result of a fracture which has occurred to the bone. To ensure that the bone can properly regenerate and fuse the fractures of the bone, it is important that the various bone portions be fixed at the desired position during bone regeneration.
The various external fixators are known for the fixation of small bones during a surgical procedure. For example, one particular type of fixator sold by Orthofix S.r.l. for small bones has two bone screw clamps with a barbell-shaped connector disposed between the bone screw clamps. The barbell-shaped connector is captured by a bushing and an apertured nut which is able to screw on to the end of each of the bone screw clamps. A cam is used to force the bushing in a direction so as to cause the bushing to force the rounded end of the barbell-shaped connector against the apertured nut to secure the position of the barbell-shaped connector with respect to the bone screw clamp. The bone screw clamp includes a body which is able to slide on the arm of the bone screw clamp and has a cover with a plurality of circular grooves disposed thereon. The circular grooves are used to receive a plurality of bone screws.
While fixators of the type described above are effective in fixating bones, they nevertheless can be the subject of certain improvements. For example, it would be useful to have a mechanism by which the member connecting the two bone screw clamps can be more rigidly secured than simply by a cam operating directly against a bushing. In addition, the barbell-shaped nature of the interconnection between the bone screw clamps limits the ability of the physician to view the fracture in that the barbell connector is not radiolucent. In addition, unless the cylindrical grooves in the bone screw clamps are made to exactly match the shape of the bone screws, the bone screw clamps would only provide two point fixation of the bone screws.